Vice President Biden will stand in for President Obama at Monday night’s Congressional Holiday Ball, the White House said Sunday.

With the president and first lady headed to Johannesburg for Nelson Mandela’s memorial service, Biden and his wife, Jill, will take over hosting duties. 

But the president’s absence, while understandable, is sure to be a disappointment to members of Congress.

Lawmakers and their families are traditionally invited to the White House in the summer for a lavish congressional picnic, which features live music and a dozen types of barbecue.

But the picnic was postponed in June because of scheduling conflicts, and then canceled in September as the president laid out his case for military strikes in response to the chemical weapons attack in Syria.

A three-sentence email from the White House Office of Legislative Affairs told lawmakers that, instead, “the president and Mrs. Obama look forward to welcoming members of Congress and their immediate families at the Congressional Holiday Ball in December.” The ball is traditionally only open to lawmakers, not their families.

The initial cancellation drew criticism from some lawmakers, who suggested the president scrapped the event out of frustration with opposition to his proposed strike on Syria. The administration ultimately abandoned that plan after Syrian leader Bashar Assad agreed to a proposal brokered by Moscow to turn over his chemical weapons.

“Congress cancels his war, he cancels our BBQ,” Rep. Justin AmashJustin AmashThe five kinds of Republicans who could primary Trump Overnight Defense: Military won't lift transgender ban until Trump sends directions | House passes national security spending | Russian sanctions bill heads to Trump Overnight Finance: House passes spending bill with border wall funds | Ryan drops border tax idea | Russia sanctions bill goes to Trump's desk | Dems grill bank regulator picks MORE (R-Mich.) tweeted.

Again, world events have intervened. The Obamas and former Secretary of State Hillary ClintonHillary Rodham ClintonAssange meets U.S. congressman, vows to prove Russia did not leak him documents High-ranking FBI official leaves Russia probe OPINION | Steve Bannon is Trump's indispensable man — don't sacrifice him to the critics MORE left Monday morning for their day-long trip, which will include a refueling stop in Senegal. 

Still, the first family will have an opportunity to sow some bipartisan good will. Joining them on their flight is former President George W. Bush, and his wife, Laura. 

The White House has not yet said when the president will return from his trip to South Africa, leaving open the question of whether Biden will be needed to fill in at holiday events planned for later this week.